Jar cap



Oct. 30, 1934. A JEDLlCKA 1,978,635

JAR GAP Filed April 18, 1934 Eig4f H. G. JEDL/CKA wgpmwymww PatentedOct. 30, 1934 JAR, CAP

.Anton George Jedlicka, Minneapolis, Minn., as-

signor to `Hancock-Nelson Mercantile Company, St. Paul, Minn., acorporation of Minnesota Application April 18, 1934, Serial No.721,218

3 Claims.

This invention relates to jar closures and it has for its general objectthe provision of an improved jar cap of that type which seals againstthe inner edge of the jar.

-5 One of 'the more specic objects of the invention is the provision ofa jar cap with internal flexible sealing disk, so co-operably arrangedas to inhibit rotation of the disk against the rough or irregular edgeof the jar when the cap is l@ screwed in place, whereby tearing of thedisk is avoided and a better seal produced.

Another object of the invention is the provision of a jar cap having .anopening in the center bounded by downwardly. extending wall 'l5 or angewhich `3o-acts with the `middle of the sealing disk, holding it spaced-from. the inside face of the cap, `permitting the peripheral `portionsof the disk to cainber under the pressure of the edge of the jar,producing pressure against the edge `of the jar which `prevents rotationof the disk. i

A further object of the invention is to ,provide a jar cap `with opencenter and depending bounding fiange as described, in-combination with aflexible sealing disk which acts as a diaphragm,

moving `under thediurnal pressure changes within the jar, and therebypreventing diffusion of the air` with gaseous contents of said jar, lthedisk exposing its maximum .area to exion when the pressure of theatmosphere exceeds the pressure within the jar and presenting a minimumarea to possible diffusion, when the pressure within the iar exceedsthat of the, atmosphere.

Still another object of the invention is the provision of a metal jarcap with paper sealing disk, the cap being open at the center to exposethe disk which may be cut out or punctured to form a discharge opening,and in which the depending flange which bounds the opening, holds the 4opaper away from the metal avoiding corrosion of the latter andobjectionable discoloration of the paper.'

Still another object of the invention is to provide a jar cap of thetype described having the peripheral wall of the central openingthreaded,

adapting the cap to a secondary utility in connection with a spout, lampburner, etc.

Other objects of the invention will appear as the following descriptionof a preferred and practical embodiment thereof proceeds.

In the drawing which accompanies and forms a part of the followingspecification and throughout the several figures of which the samecharacters of reference have been used to denote iden.-

tical parts:

Figure l is a plan view of a jar cap embodying the features of thepresent invention;

Figure 2 is a vertical diametrical section through the jar cap showingit partly screwed down on the mouth of a Mason jar; ,60

"igure 3 is a similar view showing the cap entirely screwed down andillustrating in dotted lines the iiexion of the paper disk whenatmospheric pressure exceeds that within the jar;

Figure 4 is a vertical section showing the use 65 of the jar cap as anadapter between the mouth of the jar and a spout by means of kwhich thecontents of the jar may be discharged; and

Figure 5 is a similar view showing the jar converted into a lamp byscrewing a common forni v oi' burner into the central opening in the jarcap.

Referring now in detail to the several figures the numeral 1 representsa metallic cap comprising the substantially flat and annular top portion2, provided peripherally with a down 75 Vturned and preferably integralflange 3 threaded as at 4 to receive the threaded mouth 5 of a glassjar. The cap is provided with a flexible paper disk 6 fitting thereinand preferably parained. The disk 6 is adapted to make sealing contact80 with the edge of the jar mouth when the cap is screwed tightly 'inplace. Caps with paper disks or linings adapted to seal against theinner edge of the jar mouth are known, but their use is more orv lesslimited to those classes of goods which it is not absolutely essentialto seal in an air-tight manner, forexample, pickles, preserves, etc.

i The common defect of such jar caps is the tearing of the edge of thepaper disk when the cap is screwed home due to the rotation of the diskupon 490 the rough or irregular edge of the jarniouth.,`l4 It is thuspractically impossible to get a good seal and the Vinegar or otherliquid content of the jar is apt to leak out, staining the label,corroding the outside of the lid and otherwise impairing therespectability of the jar. The fact that a good seal cannot be uniformlyobtained also renders such jar caps ineligible for the packaging ofaromatic substances, such as coffee which ordinarily lose much of theirflavor due to the escape of A the aromatic gases evolved in the jar orcontainer. The present invention provides a better seal by preventingthe rotation of the disk 6 upon the edge of the jar mouth therebyavoiding tearing of the paper disk. This it 4does through the forr105anation of a central opening 7 in the jar lid and the bent down marginof the cap which bounds said opening forming a flange 8. The lower edgeof this flange preferably lies in a transverse plane land normallyengages the paper disk 6 holding it 110 spaced from the annular topportion 2. the cap with the disk is screwed down on the jar, it isobvious from Figure 2 that the peripheral portions of the disk areforced out of their planar relation to the central portion by theincursion of the edge of the jar creating a pressure between the diskand the edge of the jarv mouth. Of course, an equal pressure isgenerated along the line of contact between the edge of the flange 8 andthe disk, but since the circumference of the flange 8 is much less thanthe circumference of the jar mouth and the flange 8 presents an edgeContact to the disk while the jar presents a atter surface, the diskwill be held fixed in its relation to the mouth of the jar, the diskremaining stationary while the cap is rotated to its final position oftightness in which position, the peripheral edge of the disk is clampedbetween the edge of the jar mouth and the top portion of the cap. Theinequalities or irregularities of the edge of the jar thus burythemselves into the paper disk under the clamping pressure, perfectingthe seal instead of tearing their way circumferentially through thepaper as is inevitably the case where the disk rotates.

Another virtue of the cap of the present invention which particularlyadapts it to a coffee package is illustrated in Figure 3. It will beunderstood from what has been stated in relation to the objects of theinvention that even though coffee may be packed in a vacuum, this vacuumis gradually supplanted by a gas, being the volatilized aromaticprinciple of the coffee and the loss of which materially deterioratesthe quality of the coffee. If the jar of coffee is closed by aninflexible lid, the pressure of the atmosphere in the coolness of thenight when the contents of the jar contract ordinarily causes leakage ofthe atmosphere into the jar `diluting the aromatic gas, and in thewarmth of the daytime, the building up of pressure within the jar canordinarily be relieved only by the leakage from the jar of some of thegaseous contents. If the closure is iiexible so that it functions as adiaphragm, the contraction and expansion of the jar can be accommodatedwithout necessitating leakage or diffusion.

It will be observed from Figure 3 that when the atmospheric pressureexceeds the pressure within rthe jar the paper disk is forced inwardlyaway from the flange 8 so that its entire area is exposed to atmosphericpressure and allowing a maximum degree of flexibility, but that when thepressure within the jar exceeds atmosphere, the paper disk 6 contactswith the edge of the flange 8 reducing the area upon which the`differential pressure can act, to the size of the opening 7 so thatonly this small area is subject to osmotic pressure. Consequently, notonly in view of the perfect seal between the disk and the edge of thejar mouth, but also in View of the differential diaphragm action of thedisk 6, the loss of aroma from the coffee package is reduced to aminimum.

When

It will be observed from Figures 2 and 3 that the flange 8 holds thepaper disk 6 out of contact with the major portion of the surface of themetal cap thus, in the event that the cap may become moist from theliquid contents of the jar, preventing corrosion of the metal anddiscoloration of the disk. This is a feature particularly advantageousin the packing of preserves or pickles.

The provision of the central opening 7 exposes the paper disk 6,affording a convenient means for gaining access to the jar by merelypuncturing or cutting out the exposed portion of the disk, therebyforming a discharge opening.

The flange 8 is preferably threaded as indicated at 9, so that aft-erthe cap has served its primary function as a leak-proof closure for ajar, it may still serve other useful purposes. For example, a spout l0as shown in Figure 4 may be threaded into the central opening andconvert the jar, or any jar for that matter with which the cap may beused, into a dispensing container for lubricating oil or the like, or byscrewing a well known form of burner 11 into the opening 7, the jartogether with the cap and burner become a complete kerosene lamp.

While I have in the above disclosure described what I believe to be apreferred and practical embodiment of my invention, it will beunderstood that the specific details of construction as shown anddescribed are merely exemplary and not to be construed as limiting thescope of the invention as claimed.

What I claim is:

1. Jar cap comprising in combination, a metallic portion having athreaded peripheral flange adapted to be screwed upon a threaded jarmouth, said metallic portion having a central opening bounded by aninwardly extending fiange, and

a flexible disk fitting within said cap with its 32.-"

central portion engaging said flange and adapted to have its peripheralportion pressed into sealing relation between the top portion and theedge of a jar mouth, when the cap is screwed upon said Jar.

2. Jar cap as claimed in claim l, the inwardly extended fiange beingthreaded.

3. Jar cap adapted to cooperate with the threaded mouth of a glass jarand a paper disk laid upon the edge of the mouth of said jar, comF jprising a metallic member having an annular top portion, a threadedflange extending downwardly from its outer periphery adapted to engagethe threaded mouth of the `iar, and a threaded flange extendingdownwardly from its inner periphery and adapted to engage the paper diskand bulge the same downwardly as the cap is screwed in place, preventingrotation of the disk and maintaining the major portion thereof spacedfrom the annular portion of said cap.

ANTON GEORGE JEDLICKA.

